Printing apparatus

ABSTRACT

A printing apparatus includes: a tube configured to form a flow channel to supply a liquid to a liquid ejecting unit configured to eject the liquid; a holding unit configured to hold the tube; and a valve unit configured to move to a closed position to press and close the tube held by the holding unit with a pressing portion from an open position to open the tube held by the holding unit, and to move to the open position from the closed position. Here, the valve unit includes a pivot shaft and moves pivotally around the shaft to move to the closed position and the open position, and a direction of extension of the pivot shaft is a direction intersecting with a direction of extension of the tube held by the holding unit.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a printing apparatus.

Description of the Related Art

There has been known a printing apparatus configured to use a tube toconnect a print head for ejecting an ink to an ink tank containing theink to be supplied to the print head. Japanese Patent Laid-Open No.2015-27741 (Reference 1) discloses an on-off valve which can close atube between a print head and an ink tank by using a pressing memberthat is linearly driven to press the tube.

According to the printing apparatus disclosed in Reference 1, the tubepressing member may fail to apply a pressure in parallel to each tube ina case of pressing a tube having a large diameter or in a case ofintegrally pressing two or more tubes. As a consequence, the tubepressing member or a tube supporting member for supporting the tube maybe inclined relative to a width direction of the tube, thus causing aleakage due to a failure to fully press the tube.

SUMMARY OF THE INVENTION

A printing apparatus according to an aspect of the present inventionincludes: a tube configured to form a flow channel to supply a liquid toa liquid ejecting unit configured to eject the liquid; a holding unitconfigured to hold the tube; and a valve unit configured to move to aclosed position to press and close the tube held by the holding unitwith a pressing portion from an open position to open the tube held bythe holding unit, and to move to the open position from the closedposition. Here, the valve unit includes a pivot shaft and movespivotally around the pivot shaft to move to the closed position and theopen position, and a direction of extension of the pivot shaft is adirection intersecting with a direction of extension of the tube held bythe holding unit.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a printing apparatus;

FIG. 2 is a schematic diagram showing a positional relation between anink tank and a print head;

FIGS. 3A to 3D are perspective views of the printing apparatus;

FIGS. 4A and 4B are schematic diagrams showing states of the ink tankand the print head;

FIG. 5 is a flowchart of an ink filling sequence;

FIG. 6 is a block diagram including a configuration of the printingapparatus;

FIGS. 7A and 7B are perspective views of an operating unit in an on-offvalve mechanism;

FIG. 8 is a perspective view showing an outline of the on-off valvemechanism;

FIGS. 9A and 9B are cross-sectional views showing the outline of theon-off valve mechanism;

FIG. 10 is a cross-sectional view showing an outline of the on-off valvemechanism;

FIG. 11 is a perspective view of the on-off valve mechanism;

FIGS. 12A and 12B are side views of on-off valve mechanism; and

FIG. 13 is a cross-sectional view showing the outline of the on-offvalve mechanism.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention will be described below withreference to the drawings. It is to be noted that the followingembodiments do not intend to limit the scope of the present inventionand that all the combinations of the features described in theembodiments are not always essential. The same constituents in theembodiments will be denoted by the same reference signs in the followingdescription.

In the present specification, the term “printing” (which may also bereferred to as “print”) is not limited to a case of forming significantinformation such as characters and graphics, but encompasses formationof all significant and insignificant information. This term is alsoassumed to broadly include formation of images, figures, patterns, andthe like on a print medium as well as processing of a print mediumregardless of whether or not these objects are materialized so as to bediscernible to human eyes.

Meanwhile, the term “ink” (which may also be referred to as “liquid”)should also be interpreted in a broad sense as with the definition ofthe “printing” mentioned above. Accordingly, this term is assumed torepresent a liquid which serves to form images, figures, patterns, andthe like, to process a print medium, and to modify an ink (such ascoagulation and insolubilization of a colorant contained in the ink tobe applied to the print medium) in the case where the liquid is appliedonto the print medium.

In addition, the term “print medium” not only includes paper used ingeneral printing apparatuses but also broadly includes media that canaccept the ink as typified by cloth, plastic films, metal plates, glass,ceramics, wood, leather, and the like.

First Embodiment

<Configuration of Printing Apparatus>

FIG. 1 is a perspective view showing a printing apparatus 100 thatrepresents an example of a liquid ejecting apparatus of the presentembodiment. FIG. 1 shows a partial configuration of the printingapparatus 100. The printing apparatus 100 includes ink tanks 11 thatcontain inks, a print head 62 that ejects the inks supplied from the inktanks 11 through ink supply channels 51, and a carriage 61 that holdsthe print head 62. The carriage 61 is configured to scan a print medium(not shown) in a direction orthogonal to a direction of transportationof the print medium, and an image is printed on the print medium by acombination of scanning by the carriage 61 and ejection from the printhead 62.

Although the present embodiment describes an example of the printingapparatus, the same applies to a case of a liquid ejecting apparatus.For example, such a liquid ejecting apparatus may include a liquidcontainer that contains a liquid, a liquid ejecting unit that ejects theliquid supplied from the liquid container through a liquid supplychannel, and a liquid ejecting unit holder that holds the liquidejecting unit. The description will be given in the present embodimentby using the printing apparatus 100 as the example of the liquidejecting apparatus.

Each ink tank 11 may be a first ink tank 111 or a second ink tank 112.The present embodiment shows the case of providing the multiple firstink tanks 111 on the assumption of a case of using multiple types ofinks. However, in the case of using a single type of the ink, a singleink tank (such as the first ink tank 111) may only be provided.Meanwhile, the second ink tank 112 having a larger capacity than that ofthe first ink tank 111 may be provided in the case of using a largeamount of the ink. Without limitations to the foregoing, only the secondink tanks 112 may be provided or the first ink tanks 111 and the secondink tank 112 may be provided as in the present embodiment. In the caseof providing two or more ink tanks 11, the ink tanks 11 may be providedon the right and the left relative to the center of the apparatusdepending on the size of the printing apparatus 100, or provided only onone side. In the present embodiment, three color ink tanks 111 that cancontain cyan ink, magenta ink, and yellow ink, respectively, areprovided as the first ink tanks 111. Meanwhile, one black ink tank 112that can contain black ink is provided as the second ink tank 112.Configurations of other components shown in FIG. 1 will be describedlater.

The printing apparatus 100 includes feeding rollers (not shown) thatfeed the print media, transportation rollers (not shown) that transportthe print media, and discharge rollers (not shown) that discharge theprint media. The print head 62 is detachably mounted on the carriage 61and configured to eject the inks onto a surface of a print mediumtransported by the transportation rollers, thus printing an imagethereon. Moreover, the printing apparatus 100 includes an ink suctionmechanism 64 (see FIG. 4B) provided with a suction cap 65. In order torecover an ejection performance of the print head 62, the printingapparatus 100 brings the suction cap 65 into contact with the print head62, and suctions the inks from ink ejection ports 63 (see FIG. 4B) ofthe print head 62 by using the ink suction mechanism 64. Here, the inksuction mechanism 64 includes a tube connected to the suction cap 65,and a suction pump serving as a suctioning unit, for example.

The present embodiment describes an example in which the print head 62ejects the inks in accordance with a movement associated with scanningby the carriage. However, the present invention is not limited only tothis configuration. The print head may be of a so-called line type,which is provided with ink ejection ports in a region corresponding to awidth of the print medium and configured to print images on the printmedium without scanning by the carriage.

FIG. 2 is a schematic diagram showing a positional relation between theink tank 11 and the print head 62. A supply tube 17 constituting the inksupply channel 51 for supplying the ink to the print head 62 is attachedto the ink tank 11. Moreover, a tube constituting an atmosphericcommunicating channel 54 to establish communication of the inside of theink tank 11 (a buffer chamber 16) with the atmosphere is connected tothe ink tank 11. The supply tube 17 is formed from a flexible materialsuch as an elastomer. Valve units 53 for blocking communication of aliquid or the air are provided at a portion of the ink supply channel 51between the ink tank 11 and the print head 62 and at a portion of theatmospheric communicating channel 54 between the ink tank 11 and anatmosphere communicating opening 52, respectively.

The valve units 53 include a black side valve unit and color side valveunits. The black side valve unit closes the ink supply channel 51 andthe atmospheric communicating channel 54 connected to the black ink tank112, respectively. The color side valve units close the ink supplychannels 51 and the atmospheric communicating channels 54 connected tothe color ink tanks 111, respectively. In the meantime, an on-off valvemechanism 160 to shut off the communication of the liquid or the air isprovided at a portion of each ink supply channel 51 between the valveunit 53 and the print head 62. The on-off valve mechanisms 160 include ablack side on-off valve mechanism and color side on-off valvemechanisms. The black side on-off valve mechanism closes the ink supplychannel 51 connected to the black ink tank 112. The color side on-offvalve mechanisms close the ink supply channels 51 connected to the colorink tanks 111, respectively. Each on-off valve mechanism 160 includesvarious components. Here, the black side on-off valve mechanism and thecolor side on-off valve mechanisms may use the same components in commonor use different components from each other. Details of the on-off valvemechanisms will be described later. Differences in role between theon-off valve mechanism 160 and the valve unit 53 will also be describedlater.

In the printing apparatus 100 of the present embodiment, a liquid-gasreplacement portion 15 of the ink tank 11 is located at a position lowerby an amount H in a height direction than the ink ejection ports 63 ofthe print head 62 in order to prevent a leakage of the ink from the inkejection ports 63 of the print head 62. In other words, a negativepressure originating from a water head difference corresponding to theheight H is applied to the ink ejection ports 63. Meanwhile, the bufferchamber 16 is provided at a lower part of the ink tank 11. The bufferchamber 16 can store the ink to be pushed out in the case of destructionof a meniscus in the liquid-gas replacement portion 15 due to expansionof the air inside the ink tank 11 caused by an atmospheric pressurevariation or a change in temperature. Thus, it is possible to suppressthe leakage of the ink from the ink tank 11 through the atmosphericcommunicating channel 54. In FIG. 2 as well as FIGS. 4A and 4B to bedescribed later, an open state of each of the valve units 53 and theon-off valve mechanism 160 is indicated with a dashed line and a closedstate thereof is indicated with a solid line.

Next, a configuration of an ink supply system and a flow from a point ofinjection of the ink to a point to enable image printing in the presentembodiment will be described with reference to FIGS. 3A to 5 . FIGS. 3Ato 3D are perspective views of the printing apparatus 100 according tothe present embodiment. FIGS. 3A to 3D are the perspective viewsillustrating a process of transition from a state in FIG. 3A to a statein FIG. 3D in which a user can inject the ink into the ink tank 11.FIGS. 4A and 4B are schematic diagrams showing states of the ink tank 11and the print head 62 according to the present embodiment.

As shown in FIG. 3A, the printing apparatus 100 includes a third covermember 41, which is provided with a mechanism for reading an image on aloaded original document and is pivotally supported by the printingapparatus 100 in an openable and closable manner. Note that the thirdcover member 41 may be a reading mechanism to read the image on theoriginal, or may be an access cover constituting an external uppersurface which exposes part of internal components of the printingapparatus 100 in order to remove the print medium that causes atransportation failure in the course of image printing. The ink tank 11is installed on a front surface side (+y direction side) of the printingapparatus 100 so that the user can easily inject the ink into the inktank 11. As described above, the four ink tanks 11 in total, namely, thethree color ink tanks 111 and the black ink tank 112 are provided inpresent embodiment. However, the types and the number of the ink tanks11 are not limited to this example. For instance, more than four inktanks 11 may be provided in order to improve quality of image printingon the print medium.

In the case where the user injects the ink into the ink tank 11, theuser first turns the third cover member 41 upward and sets the thirdcover member 41 to the open state as shown in FIG. 3B. As the thirdcover member 41 is turned by a predetermined amount, the open state ofthe third cover member 41 can be maintained by use of a lock mechanism(not shown). Here, a cover sensor 18 is installed at a housing 19 and iscapable of detecting the open state or the closed state of the thirdcover member 41. The cover sensor 18 is not limited to a mechanicalsensor designed to detect mechanical contact. The cover sensor 18 may bemay be an optical sensor, for example. Here, it is possible to releasethe lock mechanism by further turning the third cover member 41 upward.This action makes it possible to close the third cover member 41. Byopening the third cover member 41, the internal components of theprinting apparatus 100 are exposed and the user can operate a secondcover member 21 (see FIGS. 3B and 1 ).

The second cover member 21 is pivotally supported in such a way as to bemovable between a position to fall forward (a closed lid position) and aposition to be lifted up (an open lid position). The ink tanks 11 areprovided with the second cover members 21, respectively. To be moreprecise, the black ink tank 112 is covered with a black second covermember 212 and the three color ink tanks 111 are integrally covered witha single color second cover member 211. The black second cover member212 and the color second cover member 211 will be collectively referredto as the second cover member 21. Although the black second cover member212 and the color second cover member 211 are formed into differentshapes in present embodiment, these cover members may be formed into thesame shape instead.

A first cover member 12 to close the ink tank 11 appears in the casewhere the user operates the second cover member 21 from the closed lidposition to the open lid position (see FIGS. 1, 3C, and 4B). The firstcover member 12 is pivotally supported in such a way as to be movablebetween a position to close the ink tank 11 (a closed tap position) anda position to be lifted up (an open tap position). An injection port 14provided at an upper part of the ink tank 11 for user in injecting theink appears in the case where the user operates the first cover member12 from the closed tap position to the open tap position (see FIGS. 3Dand 4A).

The first cover member 12 is provided with a seal member 13 formed froman elastic body such as rubber. By operating the first cover member 12to the closed tap position, the seal member 13 closes the injection port14 so as to prevent the leakage of the ink contained in the ink tank 11.In the present embodiment, the valve unit 53 acts in conjunction withthe operation to lift the first cover member 12, thus closing the inksupply channel 51 and the atmospheric communicating channel 54,respectively (FIG. 4A).

The user can inject the ink into the ink tank 11 by putting a container(not shown) containing the ink into the injection port 14. After theinjection of the ink is completed, the user operates the first covermember 12 to the closed tap position again. The valve unit 53 acts inconjunction with this operation, thus opening the ink supply channel 51and the atmospheric communicating channel 54, respectively (see FIG.4B). Thereafter, the user operates the second cover member 21 to theclosed lid position, thus closing the third cover member 41. Theprinting apparatus 100 can detect the closure of the third cover member41 by using the cover sensor 18 configured to detect the position of thethird cover member 41. Upon detection of the closure of the third covermember 41, the printing apparatus 100 brings the suction cap 65 intocontact with the print head 62 as shown in FIG. 4B in order to fill theink supply channel 51 with an ink L inside the ink tank 11. Then, theink suction mechanism 64 carries out a suctioning operation to suctionthe ink L from the ink ejection ports 63. The supply tube 17constituting the ink supply channel 51 is filled with the ink as aconsequence of this suctioning operation. Moreover, it is possible toconduct the suctioning operation while applying a larger negativepressure to the ink ejection ports 63 by carrying out on-off control ofthe on-off valve mechanism 160 at the time of this suctioning operation.To be more precise, the suction pump of the ink suction mechanism 64 isdriven in the state of capping the print head 62 with the suction cap 65while closing the on-off valve mechanism 160. In this way, the negativepressure is charged between the on-off valve mechanism 160 and the inkejection ports 63 of the print head 62. Then, as the suction pump isstopped and the on-off valve mechanism 160 is opened, the print head 62is filled with the ink by means of the charged negative pressure. In themeantime, the on-off valve mechanism 160 also has a role in closing theink supply channel 51 so as to block the ink leakage in the case ofmoving the printing apparatus 100.

As described above, the ink supply channel 51 is provided with the twotypes of the valves in the present embodiment, namely, the valve unit 53and the on-off valve mechanism 160, which have the functions independentof and different from each other. Specifically, the valve unit 53 closesthe ink supply channel 51 in the case of filling the ink tank 11 withthe ink and opens the ink supply channel 51 in other cases. On the otherhand, the on-off valve mechanism 160 closes the ink supply channel 51 inorder to suppress the ink leakage or in the case of conducting efficientsuctioning at the time of filling the ink. Details of the on-off valvemechanism 160 will be described later.

In the state filled with the ink as described above, as the ink isejected from the ink ejection ports 63 in the case of printing an imageon the print medium, for example, the ink is supplied from the ink tank11 to the print head 62 in an amount equivalent to an amount of the inkdischarged from the print head 62. The ink is continuously supplied fromthe ink tank 11 to the print head 62 until the ink in the ink tank 11falls below a predetermined amount.

The above-described example has explained the case where the userconducts the opening and closing operations by operating the first covermember 12, the second cover member 21, and the third cover member 41.Instead, the opening and closing operations may be carried outautomatically by means of control inside the printing apparatus 100.

<Ink Filling Sequence>

FIG. 5 is a flowchart of an ink filling sequence. In the case where theink filling sequence is started, the printing apparatus 100 moves thecarriage 61 that holds the print head 62 to a suctioning positionopposed to the suction cap 65 in S51 to begin with. In S52, the printingapparatus 100 brings the suction cap 65 into contact with the print head62. In S53, the printing apparatus 100 carries out the suctioningoperation to suction the ink from the ink ejection ports 63 of the printhead 62 by using the suction cap 65. In this instance, the suctioningoperation may be carried out together with the on-off control of theon-off valve mechanism 160 as discussed earlier. After the completion ofthe suctioning operation, the printing apparatus 100 moves the suctioncap 65 away from the print head 62 in S54. Then, in S55, the printingapparatus 100 moves the carriage 61 from the suctioning position to astandby position. Thus, the operations of the series of the ink fillingsequence are terminated.

<Block Diagram>

FIG. 6 is a block diagram including a configuration of the printingapparatus 100 according to the present embodiment. The printingapparatus 100 includes the print head 62, an MPU 601, a ROM 602, a RAM603, a carriage motor 604, a transportation motor 605, a print headdriver 607, a carriage motor driver 608, a transportation motor driver609, and an I/F unit 613. A program that functions as an imageprocessing unit 6021 is stored in the ROM 602.

The MPU 601 controls operations of the respective units, dataprocessing, and the like. The ROM 602 stores programs and data to beexecuted by the MPU 601. The RAM 603 temporarily stores processing datato be executed by the MPU 601 and data received from a host computer600. The print head 62 is controlled by the print head driver 607. Thecarriage 61 is driven by the carriage motor 604. The carriage motor 604is controlled by the carriage motor driver 608. The feeding rollers, thetransportation rollers, and the discharge rollers are driven by thetransportation motor 605. The transportation motor 605 is controlled bythe transportation motor driver 609. The host computer 600 includes aprinter driver 610 for processing print information such as a printedimage and image quality and for communicating with the printingapparatus 100 in the case where the user issues a command to execute aprinting operation. The MPU 601 exchanges printed images and the likewith the host computer 600 through the I/F unit 613.

<Configuration of On-Off Valve Mechanism>

Next, a description will be given of a configuration and operations ofthe on-off valve mechanism 160 according to the present embodiment.FIGS. 7A and 7B are perspective views of an operating unit 161 in theon-off valve mechanism 160 according to the present embodiment. FIG. 8is a perspective view showing an outline of the on-off valve mechanism160 according to the present embodiment. FIGS. 9A and 9B arecross-sectional views showing the outline of the on-off valve mechanism160 according to the present embodiment. FIGS. 9A and 9B arecross-sectional view taken along the IX sectional line in FIG. 8 . FIG.9A is a diagram showing an open state of the on-off valve mechanism 160and FIG. 9B is a diagram showing a closed state of the on-off valvemechanism 160. FIG. 10 is a cross-sectional view showing the closedstate of the on-off valve mechanism 160 as with FIG. 9B. FIG. 11 is aperspective view of the on-off valve mechanism 160 from a differentviewpoint from that of FIG. 8 . FIGS. 12A and 12B are side views of theon-off valve mechanism 160. FIG. 12A shows the open state of the on-offvalve mechanism 160 and FIG. 12B shows the closed state of the on-offvalve mechanism 160. FIG. 13 is a cross-sectional view showing anoutline of the on-off valve mechanism 160. FIG. 13 is thecross-sectional view taken along the XIII sectional line in FIG. 8 . Thefollowing description will be given mainly with reference to FIGS. 7A to13 as appropriate.

As described above, the on-off valve mechanism 160 is the valve forclosing and opening (establishing communication of) the ink supplychannel 51 formed from the supply tube 17. As shown in FIGS. 1, 7A, 7B,and 8 , the on-off valve mechanism 160 includes the operating unit 161which is manually operable by the user. The operating unit 161 isconfigured to enable the user to perform a rotating operation by usingan operating surface 161 a. The on-off valve mechanism 160 is disposedat the ink supply channel 51 and is capable of switching between an openstate to establish communication between the ink tank 11 and the printhead 62 and a closed state to block the communication by operating theoperating unit 161. Moreover, as shown in FIGS. 7A and 7B, a print mark166 and a maintenance mark 167 are drawn at operating positions of theoperating unit 161 so as to enable the user to intuitively recognizeon-off states of a valve in the on-off valve mechanism 160. In the casewhere the operating surface 161 a of the operating unit 161 is locatedat the position of the print mark 166, the on-off valve mechanism 160 isnot closing the ink supply channel 51 and is therefore in the statewhere the ink can be supplied from the ink tank 11 to the print head 62.In other words, the printing apparatus 100 is in a state of beingcapable of printing on the print medium. On the other hand, the on-offvalve mechanism 160 closes the ink supply channel 51 in the case wherethe operating unit 161 is rotated from the position of the print mark166 to the maintenance mark 167 and the operating surface 161 a islocated on the side indicated with the maintenance mark 167. As aconsequence, the ink is not supplied from the ink tank 11 to the printhead 62. Accordingly, the user can perform an operation to replace theprint head 62 or an operation to transport the printing apparatus 100 inthe state of suppressing the movement of the ink in the ink supplychannel 51. Meanwhile, it is possible to carry out initial filling ofthe print head 62 with the ink or an operation to remove bubbles fromthe ink supply channel 51 efficiently by conducting the above-describedsuctioning operation in the closed state of the ink supply channel 51with the on-off valve mechanism 160.

The on-off valve mechanism 160 according to the present embodimentenables opening and closing operations manually and automatically bycoupling a driving unit thereto. Here, the driving unit can beelectrically driven by an external power supply. In other words, theoperating unit 161 can switch between the open state and closed state bydriving the external driving unit in addition to the manual operation ofthe user. As shown in FIG. 3B, the printing apparatus 100 includes thehousing 19. Moreover, as shown in FIGS. 7A and 7B, the housing 19includes an opening portion 190. The operating unit 161 is disposed inthe opening portion 190. Meanwhile, since the cover sensor 18 (FIG. 3B)is provided in the present embodiment, the printing apparatus 100 candetect by using the cover sensor 18 as to whether or not the operatingunit 161 is in a state operable by the user.

As shown in FIGS. 8 to 13 , the on-off valve mechanism 160 includes theoperating unit 161, the cover member 162, a receiving member 163, adisplacement member 164, a cam 165, a holding member 169, a biasingmember 170, and a driving mechanism 260.

As shown in FIGS. 8 to 9B, the cover member 162 and the holding member169 have shapes to define an arrangement route of the supply tubes 17,respectively, and hold the supply tubes 17 in the vicinity of the on-offvalve mechanism 160. In the present embodiment, one end of each supplytube 17 is connected to the print head 62 while the other end thereof isconnected to the corresponding ink tank 11. Meanwhile, the supply tubes17 of the present embodiment include supply tubes 17 a, 17 b, 17 c, and17 d. Each supply tube 17 includes a bending region which is bendablealong with the movement of the print head 62. The on-off valve mechanism160 is arranged such that the bendable region of each supply tube 17 islocated between the print head 62 and the cover member 162. In otherwords, the on-off valve mechanism 160 is disposed at a region of eachsupply tube 17 which does not move along with the movement of thecarriage 61.

As shown in FIGS. 9A to 13 , the displacement member 164 includespressing portions 164 a and 164 b that press the supply tubes 17, and afirst pivot shaft 164 c. The displacement member 164 is biased pivotallyabout the first pivot shaft 164 c in a direction toward the cam 165 tobe described later by using a not-illustrated biasing member. In themeantime, the displacement member 164 is a member which is capable ofpivotally moving about the first pivot shaft 164 c and is displaceablein a direction to interfere with the supply tubes 17. In other words,the displacement member 164 is provided in such a way as to be capableof advancing and receding to and from the supply tubes 17.

The receiving member 163 is a member for receiving the displacementmember 164 that is displaceable in the direction to interfere with thesupply tubes 17, and includes contact portions 163 a, 163 b, 163 c, and163 d, and second pivot shafts 163 e and 163 h. The second pivot shafts163 e and 163 h are fitted into a bearing portion provided to theholding member 169, and the receiving member 163 is pivotally movableabout the second pivot shafts 163 e and 163 h. The receiving member 163is provided on an opposite side to a portion provided with thedisplacement member 164 in such a way as to correspond to each supplytube 17. The receiving member 163 is biased by the biasing member 170 ina direction to come close to the displacement member 164. The receivingmember 163 is biased by the biasing member 170 toward a rotation stopper169 a of the holding member 169, thereby controlling an amount ofpivotal movement toward a portion holding the supply tube 17. Thereceiving members 163 are provided for the respective tubes, and eachreceiving member 163 is biased by the biasing member 170 toward therotation stopper 169 a of the holding member 169. Meanwhile, eachreceiving member 163 includes a pivot shaft. In the present embodiment,the pivot shafts of the receiving members 163 corresponding to thecontact portions 163 a, 163 b, and 163 c are the second pivot shafts 163e. Although FIG. 9 shows the second pivot shaft 163 e corresponding tothe contact portion 163 a, the second pivot shafts 163 e of thereceiving members 163 corresponding to the contact portions 163 b and163 c are also included on the back side of the sheet surface. The pivotshaft of the receiving member 163 corresponding to the contact portion163 d is the second pivot shaft 163 h (see FIG. 13 ). Although thedescription has been given of the example of providing the pivot shaftsfor the respective receiving members 163, the pivot shafts only need tobe provided independently of two or more receiving members 163. In thiscontext, the single second pivot shaft 163 e may be shared as the pivotshafts for the receiving members 163 corresponding to the contactportions 163 a, 163 b, and 163 c, for example.

The present embodiment provides the pressing portion 164 a of thedisplacement member 164 which acts on the first tubes, and the contactportions 163 a, 163 b, and 163 c of the receiving members 163corresponding thereto (see FIGS. 12A and 12B). Moreover, the presentembodiment provides the pressing portion 164 b of the displacementmember 164 which acts on a second tube, and the contact portion 163 d ofthe receiving member. The first tubes are the supply tubes 17 a, 17 b,and 17 c for cyan, magenta, and yellow, for example. The second tube isthe supply tube 17 d for black. As described above, the presentembodiment is configured to press the supply tubes by using the twopressing portions 164 a and 164 b.

The description will be continued with reference to FIGS. 9A and 9B.Note that FIGS. 9A and 9B show the supply tube 17 a as an example.Accordingly, the description will be given below of the exampleconcerning the pressing portion 164 a and the contact portion 163 a thatact on the supply tube 17 a. Unless specifically stated otherwise in thedescription, the same explanations will apply to the pressing portions164 a and 164 b of the displacement member 164 which act on theremaining supply tubes 17 b, 17 c, and 17 d, and to the contact portions163 b, 163 c, and 163 d of the receiving members 163. The displacementmember 164 and each receiving member 163 are pivotally movably supportedso as to be able to come close to and recede from each other, and adirection of extension of pivot shafts thereof is provided along adirection of the sheet surface (y direction) of FIGS. 9A and 9B, whichis a direction intersecting (at right angle in this example) with a longdirection (x direction in FIGS. 9A and 9B) of the tubes. Accordingly,even in a case where diameters of the tubes or thicknesses of the tubesvary and there are differences in reactive force in y direction amongthe tubes, inclinations of the pressing portion 164 a and the contactportion 163 a in terms of a yz cross-section are regulated by the pivotshafts so that a leakage can be suppressed. Although the presentembodiment describes the example of providing the first pivot shaft 164c and the second pivot shafts 163 e and 163 h, a leakage can besuppressed likewise by using any one of the pivot shafts.

As shown in FIGS. 8 to 11 , the cam 165 includes a cam surface 165 a anda cam shaft 165 b. The cam 165 is rotated by being engaged with theoperating unit 161, thus displacing the displacement member 164. The cam165 may be provided separately from the operating unit 161 or may beintegrated with the operating unit 161. As shown in FIGS. 9A and 9B, thecam 165 is configured such that the cam surface 165 a comes into contactwith the displacement member 164. In the case where the operating unit161 is rotated manually or automatically, the cam 165 is rotated aroundthe cam shaft 165 b along with this rotation, and the displacementmember 164 pushed by the cam surface 165 a is displaced accordingly.Then, the pressing portion 164 a of the displacement member 164 pressesthe supply tube 17 a against the contact portion 163 a of the receivingmember 163, thereby crushing the supply tube 17 a. Thus, the ink supplychannel 51 is closed. In other words, the on-off valve mechanism 160 isset to the closed state. The displacement member 164 including thepressing portions 164 a and 164 b will be hereinafter referred to as avalve mechanism or more simply as a valve. As described above, thedisplacement member 164 is configured to be movable between a closedposition to close the supply tubes 17 and an open position to open thesupply tubes 17.

As shown in FIG. 8 , the driving mechanism 260 includes a drivingmechanism holding unit 261, a drive transmission gear 262 which is adrive transmission unit to transmit the drive to the operating unit 161,an intermediate gear train 263, and a motor 265. The driving mechanismholding unit 261 includes the drive transmission gear 262, theintermediate gear train 263, and the motor 265. The motor 265 includes amotor gear 264. The drive transmission gear 262 engages with theoperating unit 161. A driving force is transmitted from the motor 265connected to the external power supply (not shown) to the drivetransmission gear 262 through the intermediate gear train 263, whichrotates the operating unit 161 engaged therewith. Thus, it is possibleto close and establish communication of the ink supply channels 51automatically by displacing the displacement member with the cam 165.Here, it is possible to control a direction of drive transmission in onedirection from the motor 265 side to the operating unit 161 side byusing a worm gear for the motor gear 264 as in the present embodiment.However, the motor gear 264 is not limited only to the worm gear andother publicly known gears may be used instead.

FIGS. 12A and 12B are the side views of the configuration of the on-offvalve mechanism 160 according to the present embodiment. FIG. 12A showsthe open state of the on-off valve mechanism 160 and FIG. 12B shows theclosed state of the on-off valve mechanism 160. The pressing portions164 a and 164 b of the displacement member 164 are formed to integrallypress the supply tubes 17. The receiving members 163 include auxiliarysupporting portions 163 i, 163 j, 163 k, and 163 l located at positionscapable of coming into contact with the displacement member 164. Thereceiving members 163 and the biasing members 170 for biasing thereceiving members are provided as many as the number of the supply tubes17 so as to individually come into contact with and support the supplytubes 17, respectively. The auxiliary supporting portions 163 i, 163 j,163 k, and 163 l support the supply tubes 17 near pressing positions P(see FIG. 9B) where the supply tubes 17 are closed by the pressingportions 164 a and 164 b and the contact portions 163 a, 163 b, 163 c,and 163 d. In other words, the auxiliary supporting portions 163 i, 163j, 163 k, and 163 l are provided at the positions near the contactportions 163 a, 163 b, 163 c, and 163 d, which are different from thepositions of the contact portions 163 a, 163 b, 163 c, and 163 d.Contact surfaces of the auxiliary supporting portions 163 i, 163 j, 163k, and 163 l with the tubes are provided within widths in y direction ofthe contact portions 163 a, 163 b, 163 c, and 163 d. In other words,each of the auxiliary supporting portions 163 i, 163 j, 163 k, and 163 lincludes a substantially U-shaped groove portion so as to arrange thecorresponding tube in the groove portion. Since the positions of theauxiliary supporting portions are located at different positions fromthe pressing positions P, it is possible to regulate positions in ydirection of the supply tubes 17 without hindering the closure of thesupply tubes 17 at the pressing positions P or increasing the size in ydirection of the on-off valve mechanism 160.

<Operation to Close Supply Tube>

Next, a description will be given of an operation by the on-off valvemechanism 160 according to the present embodiment to close each supplytube 17 with reference to FIGS. 9A and 9B.

As mentioned earlier, FIGS. 9A and 9B show the cross-sectional views atthe location to close the supply tube 17 a in the on-off valve mechanism160. FIG. 9A shows the state (the open state) in which the pressingportion 164 a of the displacement member 164 does not crush the supplytube 17 a and the ink supply channel 51 establishes communication. Inthis state, the ink in the supply tube 17 a can be supplied from the inktank 11 to the print head 62 through the ink supply channel 51. If theoperating unit 161 is manually or automatically rotated in this state,the cam surface 165 a of the cam 165 is also rotated whereby the camsurface 165 a is displaced in a direction to cause the displacementmember 164 to interfere with the supply tube 17 a.

FIG. 9B shows the state (the closed state) in which the pressing portion164 a of the displacement member 164 crushes the supply tube 17 a andthe ink supply channel 51 is closed. In this state, the supply tube 17 ais crushed between the pressing portion 164 a of the displacement member164 and the contact portion 163 a of the receiving member 163 wherebythe ink supply channel 51 for the supply tube 17 a is closed. In thisstate in FIG. 9B, the supply tube 17 a is in a state of being unable tosupply the ink in the ink tank 11 to the print head 62 and in a state ofnot permitting the flow of the air therein. As shown in FIG. 9B, thereis a clearance Ls between the auxiliary supporting portion 163 iprovided to the receiving member 163 and the displacement member 164 inthe closed state of the ink supply channel 51. The receiving member 163is in a state where a reactive force at the time of closing the supplytube 17 a is equal to a biasing force of the biasing member 170.Accordingly, it is possible to apply a constant pressure with a forcerequired for closing the tube while absorbing tolerances of the supplytube 17 a and other components. By rotating the cam 165 to displace thecam surface 165 a from the state in FIG. 9B, the displacement member 164retracts toward the cam 165 by using the not-illustrated biasing member,thus returning to the state in FIG. 9A. The supply tube 17 a releasesthe closed state by its own resilience.

Here, the first pivot shaft 164 c is preferably provided atsubstantially the same height as the contact portion 163 a in terms ofthe height in z direction at the time of the closed state shown in FIG.9B. Hence, it is possible to reduce slide in x direction between thepressing portion 164 a as well as the contact portion 163 a and thesupply tube 17 a in the case of closing the tube, thereby suppressingwear. In other words, a difference in height in z direction between thefirst pivot shaft 164 c and the contact portion 163 a is preferablybelow a predetermined value. While the predetermined value can bedetermined as appropriate depending on the sizes of the components, thevalue is preferably a sufficient value for suppressing the wear. Forexample, the predetermined value may be defined as a sum of a thicknessof the pressing portion 164 a of the displacement member 164 and athickness of the contact portion 163 a of the receiving member 163.

FIG. 10 shows a state where the printing apparatus 100 is stored for along time in a posture in which the ink supply channel 51 shown in FIG.9B is closed. The ink supply channel 51 may be kept closed for a longtime for the purpose of transportation of the printing apparatus 100 andthe like. In the present embodiment, the receiving member 163 biased bythe biasing member 170 may be turned upward and the clearance Ls may belost in the case where the supply tube 17 a is stored in the closedstate for a long time. Then, the displacement member 164 receives thepressure from the receiving member 163 as the auxiliary supportingportion 163 i comes into contact with the displacement member 164 asshown in FIG. 10 , whereby the pressure applied to the supply tube 17 ais reduced. Accordingly, it is possible to suppress development ofdeformation (creap) of the supply tube 17 a attributed to the storagefor a long time.

Next, an operation to close the supply tube 17 will be described withreference to FIGS. 12A and 12B. As mentioned earlier, FIG. 12A is theside view showing the on-off valve mechanism 160 in the open state. Inthe present embodiment, a tube outside diameter and a tube thickness ofthe supply tubes 17 a, 17 b, and 17 c are different from those of thesupply tube 17 d as shown in FIG. 12A. As mentioned earlier, FIG. 12B isthe side view showing the on-off valve mechanism 160 in the closedstate. The ink supply channels 51 of the supply tubes 17 for all the inkcolors are integrally closed by the displacement of the displacementmember 164. In the closed state in FIG. 12B, reactive forces at the timeof closing the tubes vary since the tube outside diameter and the tubethickness of the supply tubes 17 a, 17 b, and 17 c are different fromthose of the supply tube 17 d. In the present embodiment, the directionof extension of pivot shafts of the displacement member 164 and thereceiving members 163 is the direction (y direction) which is orthogonalto the long direction (x direction) of the supply tubes 17. Accordingly,even in the case of integrally pressing the tubes having the differentreactive forces at the time of closure, it is possible to minimize theinclination on the yz planes of the pressing portions 164 a and 164 band the contact portions 163 a, 163 b, 163 c, and 163 d. Thus, the tubeshaving the different tube outside diameters and the differentthicknesses can be stably closed in the case of integrally closing thesetubes. Although this example explains the case where the tube outsidediameter and the tube thickness of the supply tubes 17 a, 17 b, and 17 care different from those of the supply tube 17 d, the present inventionis not limited only to this example. The same effect is obtained even ina case where at least one of the tube outside diameter and the tubethickness of the supply tubes 17 a, 17 b, and 17 c is different fromthat of the supply tube 17 d.

Meanwhile, the tube thickness of the supply tubes 17 a, 17 b, and 17 cis also different from that of the supply tube 17 d at the time ofclosing the tubes in the present embodiment. Accordingly, if a distancebetween the pressing portion 164 b and the contact portion 163 d is setto such a distance that can close the supply tube 17 d having the largerthickness, the supply tubes 17 a, 17 b, and 17 c having the smallerthickness are closed incompletely. On the other hand, if the distancebetween the pressing portion 164 a and the contact portions 163 a, 163b, and 163 c is set to such a distance that can close the supply tubes17 a, 17 b, and 17 c, the reactive force of the supply tube 17 d issignificantly increased in the case where the supply tube 17 d isclosed. Given the situation, the receiving members 163 and the biasingmembers 170 to bias the receiving members 163 are configured toindividually come into contact with and support the supply tubes 17 a,17 b, 17 c, and 17 d, respectively. In this way, it is possible toprovide the biasing forces required for the closure appropriatelydepending on the respective thicknesses of the tubes. Thus, a drivingload of the cam 165 can be reduced in the case of closing the tubeswithout unnecessarily increasing the biasing forces.

FIG. 13 is a schematic cross-sectional view of the on-off valvemechanism 160, which illustrates the first pivot shaft 164 c as well asthe pressing portions 164 a and 164 b of the displacement member 164,and the second pivot shafts 163 e and 163 h of the receiving member 163.As shown in FIG. 12A, the tube outside diameter of the supply tubes 17a, 17 b, and 17 c is different from that of the supply tube 17 d. Thepressing portions 164 a and 164 b pivotally move about the first pivotshaft 164 c. Accordingly, a separation distance La between the pressingportion 164 a and the supply tubes 17 a, 17 b, and 17 c is differentfrom a separation distance Lb between the pressing portion 164 b and thesupply tube 17 d, and La<Lb holds true. Distances from the first pivotshaft 164 c of the displacement member 164 to the pressing portions 164a and 164 b will be defined as distances Lm and Ln, respectively. In thepresent embodiment, the integrated displacement member 164 isindependently provided with the pressing portions 164 a and 164 b, andis configured such that the distances to the first pivot shaft 164 c ofthe displacement member 164 satisfy the Lm<Ln. In this way, it ispossible to integrally close the supply tubes 17 a, 17 b, 17 c, and 17 dwhile ensuring the required separation distances depending on therespective outside diameters of the supply tubes 17.

As described above, it is possible to reduce the inclinations of thedisplacement member 164 and the receiving members 163 in the widthdirection of the tubes irrespective of the tube thicknesses or thedimensions of the components even in the case of integrally pressing thetubes, thereby suppressing the occurrence of an incompletely closedstate of any of the tubes.

The description has been given of the example of the printing apparatus100 of the resent embodiment which includes a plurality of the supplytubes 17. However, the present invention is also applicable to aprinting apparatus that uses a single supply tube 17. Even in a case ofusing a tube having a large diameter, the configuration described in thepresent embodiment can suppress the occurrence of a leakage.

<Configurations of Cover Member 162 and Holding Member 169>

Next, a description will be given of configurations the cover member 162and the holding member 169. In general, it is ideal for the on-off valvemechanism to be configured to press the tubes in the directionorthogonal to the direction of extension of the tubes. However, even insuch a pressing structure, a force may be generated in the direction ofextension of the tubes due to tolerances of the components and otherfactors, whereby the tube may move in the direction of extensionthereof. The occurrence of the movement of the tubes may consume extralengths of the tubes and the taut tubes may be disconnected from jointportions. On the other hand, the occurrence of the movement of the tubemay increase the extra lengths of the tubes and the redundant tubes thatare not properly housed in a designed space may cause buckling.

Meanwhile, in the on-off valve mechanism 160 described in the presentembodiment, the displacement member 164 and the receiving member 163 areconfigured to be pivotally movable. A displacement of the pressingportion 164 a or the contact portion 163 b due to tolerances of thecomponents may generate a force to be applied in the direction ofextension of the tubes. Given the situation, the cover member 162 andthe holding member 169 of the present embodiment are provided with atube arrangement structure for suppressing the movement of the supplytubes 17 even in the case of generation of the force to be applied inthe direction of extension of the supply tubes 17.

A description will be given below with reference to FIGS. 9A and 9B ofan arrangement route for and a configuration of each supply tube 17 inthe vicinity of the on-off valve mechanism 160. The holding member 169includes a first tube regulating portion 169 b, an opposed portion 169c, and a tube supporting portion 169 d. The cover member 162 includes asecond tube regulating portion 162 a, an auxiliary contact surface 162b, and a third tube regulating portion 162 d. These constituentscollectively form an arrangement route for the supply tube 17.

The tube supporting portion 169 d of the holding member 169 has such ashape that its tip end projects above the contact portion 163 a in thecase where the supply tube 17 a is closed by the on-off valve mechanism160. The tube supporting portion 169 d supports the supply tube 17 a inthe vicinity of the pressing position P. A contact surface of the tubesupporting portion 169 d with the tube is provided within the width in ydirection of the tube supporting portion 169 d. In other words, the tubesupporting portion 169 d includes a substantially U-shaped grooveportion and the supply tube 17 a is arranged in the groove portion. Asshown in FIG. 9B, a contact portion of the tube supporting portion 169 dto come into contact with the tube is located substantially at the sameheight position in z direction (a vertical direction) as the pressingposition P in the state where the tube is closed.

The first tube regulating portion 169 b has such a shape that its tipend projects from the side supporting the supply tube 17 a with thereceiving member 163 to a position below the tube supporting portion 169d.

The second tube regulating portion 162 a is provided at a position moredistant from the pressing position P than the first tube regulatingportion 169 b is in terms of the direction of extension of the tube fromthe pressing position P. The second tube regulating portion 162 a hassuch a shape that projects in an opposite direction (−z direction) tothe direction of projection (+z direction) of the first tube regulatingportion 169 b. The second tube regulating portion 162 a has such a shapethat its tip end projects to a position below the tip end of the firsttube regulating portion 169 b. In other words, the first tube regulatingportion 169 b and the second tube regulating portion 162 a have suchshapes that their tip end portions project to a position where the tipend portions overlap each other in the direction of a projection axis(the vertical direction). The first tube regulating portion 169 b andthe second tube regulating portion 162 a form a first clearance W1 thatserves as the route for the supply tube 17 a. The first tube regulatingportion 169 b and the second tube regulating portion 162 a project frommutually opposite directions in a substantially orthogonal direction (zdirection) to the direction of extension (x direction) at the pressingposition P of the supply tube 17 a, thus forming the arrangement routefor bending the supply tube 17 a into an S-shape. Meanwhile, the tip endof the second tube regulating portion 162 a and the opposed portion 169c of the holding member 169 opposed to this tip end portion form asecond clearance W2 that serves as the route for the supply tube 17 a.The supply tube 17 a passing through the second clearance W2 is arrangedin an opposite direction (upward) from the near side to the opposedportion 169 c, and is arranged not to fall off the cover member 162 byusing the third tube regulating portion 162 d. By regulating the supplytube 17 a in x direction by using the third tube regulating portion 162d, the supply tube 17 a is kept from spreading outside of the covermember 162 by the reactive force of the tube in the case the extralength of the tube is increased due to the tolerance and the like.

The supply tube 17 a is arranged in the S-shape by using the first tuberegulating portion 169 b and the second tube regulating portion 162 a.The tube reactive force of this supply tube 17 a arranged in the S-shapeis generated in a direction to bring the supply tube 17 a into contactin such a way as to surround the tip end portion of the first tuberegulating portion 169 b or the second tube regulating portion 162 a.Since this tube reactive force is constantly generated, the contactforce with the first tube regulating portion 169 b or the second tuberegulating portion 162 a is stably generated. Accordingly, even if theforce is generated in the supply tube 17 a in the direction of extensionof the tube (x direction) from the pressing position P, a staticfrictional force against this force is generated so that the movement inthe direction of extension of the tube can be suppressed.

To be more precise, if a force acts in a direction to drag the supplytube 17 a to the pressing position P (−x direction), the contact forcebetween a side surface portion of the first tube regulating portion 169b and the supply tube 17 a is increased. Accordingly, the frictionalforce against the dragging force is increased so that the draggingmovement of the supply tube 17 a can be suppressed.

On the other hand, if a force acts in a direction to push the supplytube 17 a from the pressing position P (+x direction), the contact forcebetween a side surface portion of the second tube regulating portion 162a and the supply tube 17 a is increased. Accordingly, the frictionalforce against the pushing force is increased so that the pushingmovement of the supply tube 17 a can be suppressed.

As described above, the direction of generation of the contact forcewith the tube regulating portion attributed to the tube reactive forceis the substantially orthogonal direction to the direction of extensionof the supply tube 17 from the pressing position P. Accordingly, even incase of the occurrence of the force to drag or push the supply tube 17a, the reduction in contact force of the supply tube 17 a with the tuberegulating member is small. Thus, it is possible to suppress thereduction in frictional force and to reduce the movement of the tube.

Meanwhile, the opposed portion 169 c is provided in such a shape thatblocks the direction of extension (which is z direction at this portion)of the supply tube 17 a that is bent by the first tube regulatingportion 169 b and the second tube regulating portion 162 a. In this way,even if the supply tube 17 a is pushed toward the opposed portion 169 c,the frictional force is increased along with the increase in contactforce between the supply tube 17 a and the opposed portion 169 c, sothat the movement of the tube can be reduced.

Moreover, the supply tube 17 a is pressed against the contact portion ofthe tube supporting portion 169 d at the time of the operation to closethe tube, so that the contact force can be increased and the frictionalforce is increased as well. Thus, the movement of the supply tube 17 acan be suppressed.

As described above, it is possible to suppress the movement of thesupply tube 17 a in the case where the tube is dragged to the pressingposition P or in the case where the tube is pushed from the pressingposition P.

In the arrangement route for the supply tube 17 a, regions of the firsttube regulating portion 169 b, the tube supporting portion 169 d, andthe second tube regulating portion 162 a which come into contact withand thus bend the supply tube 17 a are preferably provided with arcforms. Since the supply tube 17 a is bent along the arc shapes and theroute is regulated accordingly, the contact area is effectivelyincreased and an effect to suppress the movement of the tube is thusenhanced.

Meanwhile, in the present embodiment, the first clearance W1 is formedinto such a width that the supply tube 17 a bent into the S-shape comesinto contact with the tube regulating portions with the reactive forceof the tube. Here, the first clearance W1 may be set smaller than theoutside diameter of the supply tube 17 a to the extent that does notcrush an inside diameter thereof. By pinching the supply tube 17 a withthe portion of the first clearance W1, it is possible to suppress themovement of the tube while reliably providing the frictional force to beapplied between the supply tube 17 a and the tube regulating portions162 a and 169 b.

In the present embodiment, the second clearance W2 is formed into such awidth that the supply tube 17 a comes into contact with the opposedportion 169 c with the reactive force of the tube. Here, the secondclearance W2 may be set smaller than the outside diameter of the supplytube 17 a to the extent that does not crush the inside diameter thereof.By pinching the supply tube 17 a with the portion of the secondclearance W2, it is possible to suppress the movement of the tube whilereliably providing the frictional force to be applied between the supplytube 17 a and the tube regulating portions 162 a and 169 b.

The on-off valve mechanism 160 of the present embodiment is configuredto open and close the supply tubes 17 by bringing the pivotally movabledisplacement member 164 into contact with the receiving members 163.However, the movement of the tubes in the direction of extension thereofcan be suppressed without limitations to this configuration.Specifically, an on-off valve mechanism that closes tubes by linearmovement can also suppress the movement of the tubes in the direction ofextension thereof by adopting the above-described configuration thatuses the cover member 162 and the holding member 169.

Meanwhile, the supply tube 17 a passing through the second clearance W2is arranged in an opposite direction to the near side of the opposedportion 169 c via the auxiliary contact surface 162 b, so as to reduce acurvature radius of the bent portion of the supply tube 17 a. Thus, itis possible to further suppress the movement of the tube by increasingthe contact force between the supply tube 17 a and the tube regulatingportions attributed to the tube reactive force. The auxiliary contactsurface 162 b is formed into a curved surface portion having an arcshape with such a curvature radius that keeps a portion of the supplytube 17 a around the second tube regulating portion 162 a from buckling.Moreover, the supply tube 17 a is arranged on an upper part of the covermember 162 with its movement in x direction being regulated by the thirdtube regulating portion 162 d.

As described above, according to the present embodiment, thedisplacement member 164 configured to press the tubes can press thetubes in parallel along the widths of the tubes in the case of pressingthe tube having the large diameter or in the case of integrally pressingthe plurality of the tubes. In other words, the displacement member 164is configured to be pivotally movable about the first pivot shaft 164 c,and the receiving member 163 to hold the supply tube 17 a is alsoconfigured to be pivotally movable about the second pivot shafts 163 eand 163 h. Moreover, the direction of extension of the pivot shafts areconfigured to extend in an intersecting direction (the width directionof the tubes) that intersects with the direction of the extension of thetubes. For this reason, even if the tubes are integrally pressed, forexample, it is possible to reduce the inclinations of the displacementmember 164 and the receiving members 163 in the width direction of thetubes irrespective of the tube outside diameters and the tubethicknesses as well as the dimensions of the components. As aconsequence, it is possible to suppress a leakage in the case ofpressing the tubes.

Meanwhile, in the present embodiment, even in the case where the supplytube 17 receives the force in the direction of extension thereof at theposition to press the tube due to the opening and closing operations bythe on-off valve mechanism 160, the tube route is regulated such thatthe frictional force is stably generated against that force.Accordingly, it is possible to suppress the movement of the supply tube17 even if the opening and closing operations are carried out by theon-off valve mechanism 160.

Other Embodiments

The above-described embodiment has explained the example in which thedisplacement member 164 presses the supply tubes 17. However, thepresent embodiment is applicable to any other modes as long as it is amode in which a flow channel is closed by pressing a tube with apressing portion. For instance, the present invention is also applicableto a mode of using a pressing portion to press a tube that is connectedto a pump to be used at the time of a recovery operation. In otherwords, the valve mechanism described in the present embodiment isapplicable to tubes for various flow channels.

Meanwhile, the above-described embodiment has explained the example ofthe printing apparatus that performs printing by using the inks.Instead, the present invention may be applied to a flow channelopening/closing apparatus to open and close a flow channel forcirculating a liquid or a gas, which includes the above-described on-offvalve mechanism. Of course, the present invention is applicable to aprinting apparatus that includes such a flow channel opening/closingapparatus (a flow channel opening/closing mechanism).

In the meantime, the above-described embodiment has explained theexample in which the receiving member 163 is biased by the biasingmember 170 in the direction to come close to the displacement member164. However, the present invention is not limited only to this example.The same effects as those of the above-described embodiment can also beobtained from a configuration in which one of the receiving member 163and the displacement member 164 is biased in a direction to come closeto each other. In other words, the displacement member 164 does not haveto be biased in the direction to come close to the receiving member 163by the not-illustrated biasing member, and the displacement member 164may instead be biased in a direction to come close to the receivingmember 163 by another not-illustrated biasing member in a directiontoward the cam 165. In this case as well, the displacement member 164can move to the position to press and close the tube and to the positionto recede from and open the tube with the cam 165 as described above. Inthis example, the receiving member 163 may be biased by the biasingmember 170 in the direction to come close to the displacement member 164likewise. Alternatively, the receiving member 163 may be fixed to theholding member 169.

Meanwhile, the above-described embodiment has explained the example ofproviding the tube arrangement route by using the holding member 169 andthe cover member 162. Instead of using the separate members, the similartube arrangement route may be provided by a single member. In themeantime, the above-described embodiment has explained the example inwhich the plurality of tubes are provided and the tube regulatingportions project from mutually opposite directions in terms of theheight direction. However, the present invention is not limited only tothis configuration. In a case where the number of tubes is small, forexample, the tube regulating portions may have such shapes that projectfrom mutually opposite directions in terms of the width directionintersecting with (for example, being orthogonal to) the direction ofextension of the tubes.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2021-020361, filed Feb. 12, 2021, which is hereby incorporated byreference wherein in its entirety.

What is claimed is:
 1. A printing apparatus comprising: a first tubeconfigured to form a flow channel to supply a liquid to a liquidejecting unit configured to eject the liquid; a second tube configuredto form a flow channel to supply a liquid to a liquid ejecting unitconfigured to eject the liquid; a holding unit configured to hold thefirst tube and the second tube, wherein the holding unit includes afirst auxiliary supporting portion configured to regulate movement in awidth direction of the first tube and includes a second auxiliarysupporting portion configured to regulate movement in a width directionof the second tube; and a valve unit configured to close the first tubeand the second tube at a closed position by pressing the first tube andthe second tube with a pressing portion, and to open the first tube andthe second tube at an open position, wherein the valve unit is pivotallymovable about a pivot shaft from the open position to the closedposition, and a direction of extension of the pivot shaft is a directionintersecting with a direction of extension of the tube held by theholding unit.
 2. The printing apparatus according to claim 1, whereinthe pressing portion includes a first pressing portion and a secondpressing portion, and wherein the first pressing portion presses thefirst tube in the closed position, and the second pressing portionpresses the second tube in the closed position, and wherein a distancebetween the first pressing portion and the pivot shaft in a firstdirection intersecting with an axial direction of the pivot shaft issmaller than a distance between the second pressing portion and thepivot shaft in the first direction.
 3. The printing apparatus accordingto claim 2, further comprising: biasing units configured to bias so asto cause the valve unit and the holding unit to come close relatively,wherein the holding units are provided to the respective tubes, and thebiasing units are provided to the respective holding units in such a wayas to bias so that the holding units and the valve unit come to closerelatively.
 4. The printing apparatus according to claim 2, wherein athickness of the second tube is larger than a thickness of the firsttube.
 5. The printing apparatus according to claim 2, wherein an outsidediameter of the second tube is larger than an outside diameter of thefirst tube.
 6. The printing apparatus according to claim 1, wherein theholding unit is pivotally movable with pivot shafts independentlyprovided for the tubes.
 7. The printing apparatus according to claim 1,wherein the holding unit includes a contact portion located at aposition opposed to the pressing portion at the closed position andconfigured to come into contact with the tubes, and the pivot shaft ofthe valve unit is located substantially at an equal height to thecontact portion of the holding unit.
 8. The printing apparatus accordingto claim 1, wherein each of the first auxiliary supporting portion andthe second auxiliary supporting portion is provided at a position to beable to come into contact with the valve unit in a case where the valveunit is located at the closed position, and in a state where the valveunit is located at the closed position, the pressing portion presses thetubes, and a clearance is formed between the valve unit and each of theauxiliary supporting portions.
 9. The printing apparatus according toclaim 8, wherein the auxiliary supporting portions are is not opposed tothe pressing portion in a state where the valve unit is located at theclosed position.
 10. A printing apparatus comprising: a tube configuredto form a flow channel to supply a liquid to a liquid ejecting unitconfigured to eject the liquid; a valve unit configured to move to aclosed position to press to close the tube and to an open position notto close the tube; and a first tube regulating portion and a second tuberegulating portion projecting in mutually opposite directions in anintersecting direction intersecting with a direction of extension of thetube, wherein a position of tip end portion of the first tube regulatingportion and a position of part of the second tube regulating portionoverlap each other in the intersecting direction, the first tuberegulating portion and the second tube regulating portion form a firstclearance in the direction of extension, and the tube is arranged topass through the first clearance.
 11. The printing apparatus accordingto claim 10, further comprising: an opposed portion located more distantfrom a pressing position where the tube is pressed by the valve unitthan the first tube regulating portion is, and opposed to the tip endportion of the second tube regulating portion, a tip end portion of thesecond tube regulating portion and the opposed portion form a secondclearance in the intersecting direction, and the tube is arranged topass through the second clearance.
 12. The printing apparatus accordingto claim 11, wherein the second tube regulating portion includes acurved surface portion located on an opposite side of a side to form thefirst clearance, and the tube passing through the second clearance isarranged to pass through the curved surface portion and to be regulatedby a third tube regulating portion configured to regulate the tube. 13.The printing apparatus according to claim 11, further comprising: a tubesupporting portion configured to support the tube between the pressingposition to the first tube regulating portion; and a contact portionopposed to the valve unit at the pressing position, wherein the tubesupporting portion projects beyond the contact portion in theintersecting direction.
 14. The printing apparatus according to claim11, wherein the first clearance is smaller than an outside diameter ofthe tube.
 15. The printing apparatus according to claim 11, wherein thesecond clearance is smaller than an outside diameter of the tube. 16.The printing apparatus according to claim 11, wherein the intersectingdirection is a vertical direction.